Make request headers validation configurable, close AsyncHttpClient#1044

Author: slandelle

client/src/main/java/org/asynchttpclient/BoundRequestBuilder.java

@@ -12,11 +12,15 @@
  */
 package org.asynchttpclient;
 
-
 public class BoundRequestBuilder extends RequestBuilderBase<BoundRequestBuilder> {
 
     private final AsyncHttpClient client;
 
+    public BoundRequestBuilder(AsyncHttpClient client, String method, boolean isDisableUrlEncoding, boolean validateHeaders) {
+        super(method, isDisableUrlEncoding, validateHeaders);
+        this.client = client;
+    }
+
     public BoundRequestBuilder(AsyncHttpClient client, String method, boolean isDisableUrlEncoding) {
         super(method, isDisableUrlEncoding);
         this.client = client;

client/src/main/java/org/asynchttpclient/RequestBuilder.java

@@ -18,9 +18,8 @@
 import io.netty.handler.codec.http.HttpMethod;
 
 /**
- * Builder for a {@link Request}. Warning: mutable and not thread-safe! Beware
- * that it holds a reference on the Request instance it builds, so modifying the
- * builder will modify the request even after it has been built.
+ * Builder for a {@link Request}. Warning: mutable and not thread-safe! Beware that it holds a reference on the Request instance it builds, so modifying the builder will modify the
+ * request even after it has been built.
  */
 public class RequestBuilder extends RequestBuilderBase<RequestBuilder> {
 
@@ -29,13 +28,17 @@ public RequestBuilder() {
     }
 
     public RequestBuilder(String method) {
-        super(method, false);
+        this(method, false);
     }
 
     public RequestBuilder(String method, boolean disableUrlEncoding) {
         super(method, disableUrlEncoding);
     }
 
+    public RequestBuilder(String method, boolean disableUrlEncoding, boolean validateHeaders) {
+        super(method, disableUrlEncoding, validateHeaders);
+    }
+
     public RequestBuilder(Request prototype) {
         super(prototype);
     }

client/src/main/java/org/asynchttpclient/RequestBuilderBase.java

@@ -66,7 +66,7 @@ public abstract class RequestBuilderBase<T extends RequestBuilderBase<T>> {
     protected Uri uri;
     protected InetAddress address;
     protected InetAddress localAddress;
-    protected HttpHeaders headers = new DefaultHttpHeaders();
+    protected HttpHeaders headers;
     protected ArrayList<Cookie> cookies;
     protected byte[] byteData;
     protected List<byte[]> compositeByteData;
@@ -89,8 +89,13 @@ public abstract class RequestBuilderBase<T extends RequestBuilderBase<T>> {
     protected NameResolver nameResolver = JdkNameResolver.INSTANCE;
 
     protected RequestBuilderBase(String method, boolean disableUrlEncoding) {
+        this(method, disableUrlEncoding, true);
+    }
+
+    protected RequestBuilderBase(String method, boolean disableUrlEncoding, boolean validateHeaders) {
         this.method = method;
         this.uriEncoder = UriEncoder.uriEncoder(disableUrlEncoding);
+        this.headers = new DefaultHttpHeaders(validateHeaders);
     }
 
     protected RequestBuilderBase(Request prototype) {
@@ -177,12 +182,15 @@ public T addHeader(CharSequence name, String value) {
     }
 
     public T setHeaders(HttpHeaders headers) {
-        this.headers = headers == null ? new DefaultHttpHeaders() : headers;
+        if (headers == null)
+            this.headers.clear();
+        else
+            this.headers = headers;
         return asDerivedType();
     }
 
     public T setHeaders(Map<String, Collection<String>> headers) {
-        this.headers = new DefaultHttpHeaders();
+        this.headers.clear();
         if (headers != null) {
             for (Map.Entry<String, Collection<String>> entry : headers.entrySet()) {
                 String headerName = entry.getKey();
@@ -376,7 +384,7 @@ public T setProxyServer(ProxyServer proxyServer) {
         this.proxyServer = proxyServer;
         return asDerivedType();
     }
-    
+
     public T setProxyServer(ProxyServer.Builder proxyServerBuilder) {
         this.proxyServer = proxyServerBuilder.build();
         return asDerivedType();
@@ -529,12 +537,12 @@ public Request build() {
         Uri finalUri = rb.computeUri();
         Charset finalCharset = rb.computeCharset();
         long finalContentLength = rb.computeRequestContentLength();
-        
+
         // make copies of mutable internal collections
         List<Cookie> cookiesCopy = rb.cookies == null ? Collections.emptyList() : new ArrayList<>(rb.cookies);
         List<Param> formParamsCopy = rb.formParams == null ? Collections.emptyList() : new ArrayList<>(rb.formParams);
         List<Part> bodyPartsCopy = rb.bodyParts == null ? Collections.emptyList() : new ArrayList<>(rb.bodyParts);
-        
+
         return new DefaultRequest(rb.method,//
                 finalUri,//
                 rb.address,//